My audio skills are limited at best, but you can always teach a young dog a new trick- censoring flattened audio. It was my understanding that you needed all the tracks separated in order to do this cleanly. I learned a new way- I’m sure this is sound design 101 but for video guys it might be something new. Why not just isolate the word or phrase in question, and reverse that section!

Here’s the quickest way to do this- Take the blade tool and cut on either side of the word.
Hit Command+J to bring up the Time Remap dialog box, and check reverse.

Example, the lyric I had to abolish were “hydro”

Listen to the before: Hydro Before
Listen to it after: Hydro After

Simple.